I suspect you won't get the SIM to authenticate in the US without a credit to the account, as it would be roaming using `conventional' inter-carrier signalling.
When you say a `300 number' - what do you mean? Not familiar with this term (fx: sorry).
No doubt Inquisitor will be along in a moment to give us the correct info...
+Steve
[size=2]Steve Gold
PO Box 1014, Sheffield S10 5YG, UK
Home mobie: Telefonica O2
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